Small-shot cartridges containing biodegradable separators

ABSTRACT

The invention relates to small-shot cartridges containing biodegradable separators. Depending on the respective intended utilization, small-shot cartridges contain either scaling disks or cup-shaped wads that are referred to as separators and that separate the charge from the pellets. The cup-shaped wads usually consist of plastic, for example LDPE (low density polyethlene) or similar materials. The scaling disks may consist of plastic, but also of other materials, for example of cardboard, felt, fibers or combinations thereof. These materials may lead to sealing problems and may impair interior ballistics, the trajectory of the projectile in the barrel, and ignition and combustion processes. The separators are ejected from the barrel by the impact of the shot and are left behind during hunting in the countryside or during shooting in the shooting gallery, especially the non-biodegradable plastic materials constitute an environmental hazard. According to the invention, the separator ( 1 ) is therefore produced from a non-brittle, biodegradable material that is resistant to the temperatures of the propellants while it does not impair the function of the separator and that is completely biodegradable when stored under the conditions of comprising.

[0001] The invention relates to a separating means between charge andshot in a small-shot cartridge.

[0002] Depending on the intended purpose, shot cartridges contain eithersealing disks or cup-shaped wads, called separators, which separate thecharge from the shot. The cup-shaped wads consist as a rule of plastic,e.g., LDPE (low-density polyethylene) or comparable materials. Thesealing disks can also consist of materials other than plastic, forexample cardboard, felt, fibers or combinations of same. Such materialscan lead to sealing problems and thus to interference with the internalballistics, the shot development in the barrel, and the ignition andcombustion processes.

[0003] If these separators are ejected out of the barrel by firing andare left in the environment by the hunters, the rot-resistant plastics,especially, contaminate the environment.

[0004] The problem of the invention is to configure the separators suchthat they no longer pollute the environment and will at the same timeimprove the internal ballistics.

[0005] The solution of the problem is achieved by the fact that theseparators, the sealing disk of the invention and the cup-shaped wads ofthe invention, are made from biodegradable, non-brittle materials whichwithstand the thermal stress of the propellant gases without anydestruction to impair their function, and when left under compostingconditions they are fully biodegradable, and furthermore are given ashape which results in an optimum seal against the hot gases of thepropellent charge.

[0006] The biodegradable materials of the separators for example Bayer'splastic BAK * advantageously permit degradation in the earth by rottingin a reasonable time. When used in shooting galleries they can beeliminated with household wastes or by composting. The plastic can bestrengthened, for example with biologically acceptable fibers such asnatural fibers, carbon fibers, glass fibers or mineral fibers.

[0007] The configuration of the cup-shaped wads with reinforced diskspermits optimum propulsion and clean guidance of the shot. Thecushioning portion is so configured that a uniform transfer of the gaspressure to the shot packet and hence to the shot cluster is assured.

[0008] The novel shape and the new materials of the separatorsadvantageously result in a uniform spread of the shot cluster.

[0009] The invention is further explained with the aid of examples.

[0010]FIG. 1 is a lateral elevation of an H-shaped disk in section,

[0011]FIG. 2 a longitudinal section of a cup-shaped wad of theinvention, and

[0012]FIG. 3 a plan view thereof.

[0013]FIG. 1 shows an H-shaped separator 1 according to the invention,made of a biodegradable plastic. The outside diameter 2 and the diameter3 of the reinforced middle section 4 as well as the thickness of thedisk are related to one another such that the forces of the gas thrustare distributed over the entire disk surface against the shot. The goodsealing of the disk 1 against the cartridge wall is achieved by the rims7 on both sides which taper by the angle 6 to a thickness of about 0.4to 0.5 mm, which thus act like sealing lips conforming to the shellwall. The angle 6 is approximately between 15 and 20 degrees. Thecentral part 4 also tapers at the same angle 6. With an outside diameter2 of about 18.6 mm according to the shotgun gauge, and an overall height9 of 7.2 mm, the thickness 5 of the disk is 3 mm, and the diameter 3 ofthe middle section 4 is 7 mm at its surface. Since the sealing disk 1 isof symmetrical shape it is not necessary to perform its installation inone particular direction, which facilitates the assembly of thecartridge.

[0014]FIG. 2 shows a cupped wad 10 in longitudinal section. The diameter11 is in conformity with the shotgun gauge and the overall height 12, 40mm in the present embodiment, is divided into the height 13 of the cup14 for the shot, here 23 mm, the height 15 of the cushioning part 16,here 9.5 mm, and the height 17 of the cup-shaped sealing part 18, here7.5 mm, the annular wall of which conforms to the cartridge shell. Thecushioning part 16 consists of two thin-walled V-shaped sections 19whose apices are opposite one another, as can be seen in FIG. 3. The cup14 has uniformly distributed over its circumference four slits 21reaching to the bottom of the cup and running in the direction of thecentral axis 22. The individual wall segments act like flexible bladeswhich facilitate the release of the shot charge when it leaves thecartridge. Here, too, the shape of the middle part permits a uniformtransfer of the gas pressure to the shot and an optimum seal against thebarrel.

1. Separator between charge and shot in a small-shot cartridge,characterized in that the separator (1, 10) consists of a non-brittle,biodegradable material which withstands the thermal stress of thepropellent gases without destruction impairing its function and iscompletely biodegradable when exposed to composting conditions. 2.Separator according to claim 1, characterized in that the separator isin the form of a H-shaped, symmetrically configured sealing disk (1)which has a strengthened center portion (4), that the diameter (3) ofthe central portion (4) and the outside diameter (11) of the sealingdisk (1) are so co-ordinated with one another that the forces of the gaspressure are distributed uniformly onto the shot charge over the entiredisk surface.
 3. Separator according to claim 1 or 2, characterized inthat the ratio of the outside diameter (2) of the sealing disk (1) tothe diameter (3) of the surface of the central portion (4) isapproximately 2.3 to 2.8 to
 1. 4. Separator according to claim 2 or 3,characterized in that on its top and bottom side the sealing disk (1)has symmetrically shaped upstanding portions (7) which taper towardtheir end and act as sealing lips.
 5. Separator according to any one ofclaims 2 to 4, characterized in that the central portion (4) of thesealing disk (1) as well as the upstanding portions (7) taper at thesame angle (6), and that the angle (6) is approximately between 15 and20 degrees.
 6. Separator according to claim 1, characterized in that theseparator is in the form of a cupped wad (10), that the walls of the cup(14) for the shot are given a blade-like shape by slits reaching down tothe cup bottom, that the cushioning part (16) consists of twothin-walled vshaped sections (19) whose apices (20) lie opposite oneanother, and that the sealing part (18) is cup-shaped.
 7. Separatoraccording to claim 6, characterized in that the walls of the cup (14)and of the sealing part (18) each taper toward their margin. 8.Separator according to any one of claims 1 to 7, characterized in thatthe material is reinforced by biologically unobjectionable fibers suchas natural fibers, carbon fibers, glass fibers or mineral fibers. 9.Separator according to any one of claims 1 to 8, characterized in thatthe material is a plastic.